Process of making polyvalent metallic salts of half esters of phthalic acid



adapted to Patented Oct. :28, 1930 INDIANA, AssIGNon. "10 COMMERCIAL vsomrmwrs CORPORATION, or tenant: HAUTE,-INDIANA, A conroRA'rIou'or "LAND PROCESS orMAKmG-rotYvALEN'r MnTAL Ic SALTS or HALF nsrnzasor. V ,1 PHTHALIGfACID -My invention relates to an improved.

method of preparing polyvalent metallicsalts of half esters of phthalic acid. More par ticularly, my invention relates. to amethod of preparing compounds of this type which are soluble in solvents immiscible in water.

.InCanadian Patent 260,927 of May 8, 1926,

Bruce K. Brown and Charles Bogin have disclosed the use of certain metal alky resins as components of nitrocellulose lacquer partly or completely replace varnish gums.

and 253,211,

J. Bannister and L. C. Swallen, describe the use of these materials for; the

purposes.

These metal alkyl reslns are more properly described as polyvalent metallicsaltsof 'alkyl half esters of phthalic' acid; Their structure may be expressed bythe following type formula:

coon 'Rooc I i C0OMOOC in which M represents a divalent metal, and

R an alkyl group such as methyl, ethyl, propyl, butyl, etc or an aryl group such as v phenyl, tolyl, benzyl, or cinnamyl. In place of M, polyvalent metals such as Zinc, copper,

lead, iron, aluminium, manganese, nickel, 35.

cobalt, etc., may be substituted.

Altho there are naturally some exceptions to the'general statement, the polyvalent metallic salts of half esters of phthalic acid'may be generally'characterized as solid, stable,

neutral, resin-like substances, insoluble in Water, soluble 1n organic solvents, and exerting a solvent action on nitrocellulose. The

1 zinc and iron butyl'phthalates are plastic solids similar to certain resins in some of their physical properties, thez inc compound being. colorless and the iron, reddish-brown. The

corresponding copper compound is a dry powder, bluish-green in color. Y .r V s In the past it has been the custom to prepare polyvalent metallic salts of half esters United States Serial Nos. 253,210 filed February 9, 1928, by C. W.

- .I have now discovered a method of effectingthe preparation ofthe'se compounds in the presence of water-immiscible. solvents" phthalic I acid according to the methodfldescribed below phthalate. 1

butyl-alcohol was employed, the resulting i no Drawing. Original application filed lune 13, 1 2s,se,rs1; ;2s5,=225; mvid iianalhis traum s a I Y filed July 8,1929; serialuasvasss; I o

f ai -fien bu yl Monobutyl phthalate' was firstipreparedby ,heatingphthalic anliydride with'an excess of butyl alcohol. If only afslight excess of" compoundwas used as. formed: "--I f, lioweve r,

a large excess was used," the monobutyl phthalate was generally rcrystalliz'edlout 'o-f the solution.

Sodium butyl phthalate was by neutralizing the monobutylphthalate-with sodiumfhydroxide in aqueous solution. iaqueoussolution of some-soluble zinc salt was then added in equivalent,proportions, 1 I r with rapid'agitation v I 4 The zinc-butyl phthalate obtained -inthis :mannerformed as .a very sticky semi-liquid which slowly settled to the bottom-of the reaction vessel- It was later'dissolved in some suitable solvent v and purified. by ,de-

hydration and filtration. Dehydration was accomplished by choosing a solvent forming aconstant boiling mixture, and distilling. The yields thus obtained-were low due to inclusion of the soluble zinc compound and also; of sodium butyl phthalate solution-by ,the pasty zinc butyl phthalate, There .was

also anappreciable amount lost thr u solution in'the' water. Ingeneral,many difficulf tieswereexperienced in this methodof preparation due to the stickymatiireo-f 'the co'mwhich-gives greatly improvedresults over methods previously employed. By my 'new method,";;itg is possible if. desired to omit .one step in. the procedure customarily eniployedpgThe following examples are cite :as illustrativeofmynew-process, N I,

Example-If L v 1630 grams of phthalic anhydride is added-in several portionsto agmixtur'e of 825 grams of butyl alcohol and 1000 grams of toluol, maintained at a temperature of approximately 100 C... After 'a homogene- 7 ous solution results, the heating is continued at this temperature for approximately 1 hour. This operation gives monobutyl phthalate. After cooling, a sodium 1 hydroxide solution, made up by dissolving 450 grams of 95% sodium hydroxide in v 3600 c. c. of Water, is added to the monobutyl phthalate-toluol solution until the latter is just alkaline to phenolphthalein. The'temperatu're .should be kept 'below60+70 7 C7.,i and preferably below 0., and the-mass..-

Well agitated'while the sodium hydroxide is do I ) using brom cresol purpleas the indicator.

be removed by filtration.

beingaddedJ A solution of 1600-grams-of zinc sulphate (ZnSO .7H O)"ii1 2 liters of Water is next added under good agitation and the mixture allowed to settle in a separating funnel. In'this manner, zinc butyl phthalate is obtained from the previously formed sodium butylfphthalate. After separationof the oil and water layers, the for- 'meris placed in a -flask and distillation under reduced pressure (100 mm. or less) started. This is continued until no more 'Water comes over with the toluol. If there.

is a large amount of'wa'tier present, more toluol maybe added-to the flask. It is important th'at during this" operation the temperature ofthe liquidin the flask should :not exceed approximately 80 C. After cooling, any residual zinc sulphate orsodium sulphate present in the compound may :As prev'iously pointed out, it is' possible,

if desired, to omit'in my new process] the step involving the preparation of the monovalent alkyl phthalate (e. g., sodium butyl 'phthalate); This point is illustrated'in EX- ample II described-below.

. am le 11 e i Y' i Monobutyl phthalateiis obtained as de scribed in Example I by the" interaction of 90 lbsyof phthalic anhydride and lbs. of "butyl alcohol'in the presence of,'say 300 lbs. of a petroleum hydrocarbon boiling above 100 C.- The resultingsolution is cooled to approximately 80 C. and 25.5 lbs.'of'powdered zinc oxide slowly addedwhile agitating and maintaining the temperature ap-- proximately constant. It is desirable to use moistzinc oxide or else add a small amount of Water, say 4 to '5 lbs. before the addition of the zinc, oxide, since the presence'of a small amountof water has been found to expedite the'reaction. After all of the'zinc oxide hasbeen added, agitation is continued for about one hour while still maintaining the temperature at .80 CI -At the; end of this time, the solution is tested for acidlty by titrating with standard alkali solution,

If the acidityis found tobe greater than 0 .1% (calculated as phthalic acid) approximately 1 lb. more ofzinc oxide is added and the-reacting mixture maintained at 70-80 C. for an additional half-hour. When the acidity is found to be reduced sufiiciently, the reaction kettle is closed and the reaction mixture heated for 1 hour under 25" vacuum at C. When all of the water present has been removed, the reaction product .is

allowed to @001. After standing foresee days it is filteredto remove "unusedfzincoxide,'zinc phthalate, etc. Petroleum"hydrocarbon or other solvent may b e removed by distillation, if desired.

If desired, a solvent boiling below 100 C. may be employed rinplace o .qne.-;h0: li11g above 100 C.,;as specified above. If a low boiling solvent is employed, however, it is necessary to conduct the reaction ina closed vessel to prevent the loss of the solvent; In 'analternative method of carrying out my new process, somewhat lower boiling solvents may be employed. In this case'the addition" ofthesolvent material is omitted until after the first step, e. g;, the preparation of mono- 'butyl' phthalate, has been completed: As

soon as this partoit' the reaction is over the solvent may be addedand the operationcom- 'pleted as 1 previously described, the desired advantages being obtained by the presence or the solvent during the latter steps;

7 It is distinctlyunderstood' thatthe exam-- 'plesdescribed above are cited as illustrations "of acceptable variations in my new method of preparing polyvalent metallic salts of half esters of phthalic acid and that many other similar products may be obtained in the same -manner merely bysuitably varying theconstituents entering into the reaction. For example, in place of butyl alcohol, I'. may employ any other alcohol such as methyl, ethyl, propyl, amyl, benzyl, 'cinnamyl, etc. Instead of a zinccompound', I may use a suitable compound of such polyvalent metals as iron, lead, copper, nickel, cobalt, aluminium, etc.

-As thesolvent required in the process, I may employ any material of suitable boiling point bons, petroleum hydrocarbons, and if it is not desired to separate the resulting compound, such solvents as dibutyl-phthalate and butyl stearate." V v As pointed out above, it has formerly been the customto prepare polyvalent metallic salts of half esters or. phthalic acid by carrying out the various steps of the process in the presenceof water and eventually attempting the recovery of the finished product by means 2 of various solvents. This method of. procedure led tomany diificulties and gave poor yields. By my new process of effecting the formation of these materials in the presence at the same time better yields'and a better grade of products are obtained.

This application isa division ofqmy copending application U..S. Serial No. 285,225, filed June 13,: 1928, for process of making Now havlng described my invention, what I claim as new and novel is:

I 1. The process of preparlng polyvalent metallic salts of half esters of phthalic'acid which comprises reacting alcohols and phthalic anhydride in the presence of solvents immiscible in water and-not entering appreciably into reaction with any of. the materials present, neutralizing the resulting ;-product with a moistbase of'apolyvalent' metal, andfinally recovering the said poly valent salts of half'esters of phthalic acid from the said solvents. V r g 2. The process of preparing.

polyvalent metallic salts of half esters of phthalic acid which-comprises reacting" alcohols and phthalic anhydride in the presence of coal tar hydrocarbons,-neutralizing the resulting product with a moist base of. a polyvalent metal, and finally recoveringthe said polyvalent salt of half esters of-phth'alic acid from the said coal tar hydrocarbons. 3. The process of preparing polyvalent metallic salts of halfesters of phthalic'acid which comprises reacting phenols and phthalic anhydride in the presence of coal tar hy- 7 drocarbons, neutralizing the resulting product with a moist base of a polyvalent metal,

and finally recovering the said polyvalent salt of halfesters of phthalic acid from the said coal tar hydrocarbon.

4. The process of preparing polyvalent me tallic salts of half esters of phthalic acid which comprises reacting alcohols and phtha lic anhydride in the presence of petroleum 7 hydrocarbons, neutralizing the resulting product with a moist base of a polyvalent metal, and finally recovering thesaid polyvalent salts of halfesters of phthalic acid from the said petroleum hydrocarbons. 5. The process of preparing polyvalent metallic salts of alkyl half esters of phthalic acid which comprises reacting aliphatic alcohols and phthalic anhydride, adding a petroleum hydrocarbon, neutralizing the resulting prod uct With a moist base of a polyvalent metal,

.ering' the said zinc salt comprisesreacting butyl alcohol and phthalic anhydride in the presence of solvents imthe said zinc salt of the butyl half ester of phthalic acid.

7. The process of preparing the zinc salt of the butyl half esterof phthalic acid which comprises reacting butyl alcohol and 'phthalic v i i anhydride in he presence of coal tar'hydro y nt metallic salts of half esters of phthalic acid. 7

carbons, 1 neutralizing the resulting product with most zinc. oxide, and finally recovering the said zinc salt of the butyl halfester of phthalic acid. V 7

.8. Theprocess of preparing the zinc salt of the butyl half ester of-phthalic acid which comprises reacting butyl alcohol and phth'alic anhydride in the presence of petroleumhydrocarbons, neutralizing the resulting prodv uct with moist zinc oxide, and finally recov;

' of thebutyl half ester of phthalic acid. I

9. The process of preparing the'zinc salt of theibutyl half ester of phthalic' acidiwhich" comprises reacting butyl alcohol and phthalic anhydridaiadding a petroleum hydrocarbon, I i neutralizing the resulting product with moist zincoxide and finally 'recovering'the said zinc salt of'the butyl half ester ofphthalic I acid.

lntestimony whereof Iaflix my signature.

WILLIAM'J. BANNISTER;

and finally recovering the said polyvalent salts of alkyl half esters of phthalic' acid i from the said petroleum hydrocarbon.

6. The process of preparing the zinc salt of the butyl half ester of phthalic acid which 

